Controlling Pests Naturally

Most of us plant our gardens outside, right? There are bugs, rodents and fungi out there, so it is inevitable that we might see some aphids, mites, beetles, powdery mildew, botrytis, or rodent damage. How can we create a garden that has fewer problems?

Prevent Problems. Start early. Biological measures can drastically improve your chances of resisting pests and diseases and reduce a need later for adding pesticides or fungicides. There are many ways we can do this.

Create healthy populations of pathogen and insect fighting Bacteria and Fungi in your soil. Inoculate your soil before planting and in the early stages of planting. There are many inoculants you can use, especially if you know you might have a problem. For example, try foliar spraying bacillus subtilis in your soil to later avoid mildew. Create a nutrient or tea feed with inoculants to get the beneficial bacteria systemically into plants. Many pathogens are actually systemic. Using beneficial microbes helps plants resist diseases and insects, breaks down dead matter left over by pathogens, and helps plant efficiently uptake nutrients.

Get Chitosan into your soil. Chitosan comes from from broken shells of crustaceans (crab, shrimp), similar to chitin from insects. Chitosan has many amazing benefits. It repels insects, feeds beneficial fungi, destroys none beneficial cyst nematodes, reduces environmental stress, builds immune systems in plants, helps grow and bloom, increases germination rates, and doesn’t seem to harm environment. If you make compost tea get Frass and/or Crab meal into your tea to increase the chitosan content.

Plant flowers. Simply, most things that flower attract beneficial insects. We want the bees-even the ones that sting- in our garden. Native bees are our pollinators. Planting flowers also attracts the predatory insects like ladybugs and praying mantis that eat those nasty aphids.

Plant pungent herbs such as rosemary, chamomile, lavender, mint, oregano. These plants will continually return and attract beneficial insects, but repel pathogenic fungi.

Strengthen the immune system of your plants by feeding them seaweed, silica, calcium and potassium.

Don’t over feed. Overfeeding creates weak foliage that then dies and attracts pathogens. Feed only what you need when you need.

Add predatory insects, such as ladybugs, praying mantis, Swirskii mites, and trichogramma wasps.

Treating Insect Problems

As our garden grows, so do populations of arthropods. It is a reality. What do we do when we get an overpopulation of aphids, caterpillars, or mites? There are a variety of controls that we can use that help reduce, repel or kill insect populations. Most need to be sprayed on the leaf surface and UNDER the leaf surface to work. Often just the act of spraying repels the unwanted insect! All products have manufacture’s directions and I suggest you follow them. Any product can potentially burn your crop and remember, even if a product is natural or organic it can still harm beneficial insects. If you want to minimize your impact on the environment, spray only specifically on plants with problems and spray when beneficial insects are not active. Products having the least impact on our environment are soaps, plant extracts, sulfur dust, neem products, yeast enzymes, yucca, coco, oils, sugars, certain bacteria, and diatomaceous earth. Below are products that are commercially available to help control an unwanted insect population.

  • Soap kills and deters insects. There are commercially available insecticidal soaps, so there is no guess work in the application. You have heard their brand names, such as Safer Soap. Some are certified organic. You can however create your own successfully. Some garden books recommend using Doctor Bronner’s soaps-such as peppermint or lavender soaps.
  • Neem repels insects. Neem Oil coats insect bodies, smothers them, and kills adults. Neem also has in it a compound called azadirachtin that inhibits the insect’s ability to reproduce. Neem seed meal can be added to the soil as an insect deterrent and also as a fertilizer.
  • Fish oil is a broad-spectrum insecticide and fungicide. It can burn if not spread properly. It also is a fertilizer!
  • Horticultural oils smother and repel.
  • Adding plant extracts rosemary, lavender, eucalyptus, cloves, garlic, cinnamon, and coriander deter and often kill insects. Extracts are often added to soaps and oils. Some plant extracts can be added systemically and deter insects from eating the leaves of plants.
  • Diatomaceous earth kills insects by putting diatoms into their bellies, which act like little shards of glass. It also provides plants with silica. Diatomaceous earth can be added to the soil as well as applied to leaf surfaces. Diatomaceous earth is non specific and can damage all micro arthropods.
  • Sugars are found in many organic insecticides. Molasses and Yucca seem to have an effect when mixed with other products to keep populations down.
  • Pyrethrin, made from the flowers of chrysanthramum and pyrethrum kill many insects. Pyrethrin dissipates in 24 hours. This is one of those sprays to add when beneficial insects are not active. Follow directions, do not overspray.
  • Compost tea has also been known to reduce insect populations by providing chitosan on the leaf surface and keeping the plant healthy and not very attractive to insects.
  • BT, Bacillus thurengiensis, an effective larval killing bacteria, is used to kill moths. It can also harm butterflies. It is best to spray only when butterflies are not active and only when needed.
  • Bacillus thurengiensis israelis is also a larval killer. It is effective in the soil to control fungal gnats, mite larvae, root nematodes, and termites.
  • Spinosad, certified organic, is a by product of an aggressive bacteria.
  • Beauvaria hassiana and Metaharzanium are parasitic fungi that help with many insects.
  • Sulfur dust. This flowable powder of 90% sulfur is effectively being used on the russet mite population. It cannot be mixed with any oil! It is easy to burn your plants with sulfur, so following instructions is important. However, plants NEED sulfur, so a small dose of sulfur is actually beneficial. Sadly though, sulfur kills beneficial insects and bacteria and fungi as well, so use it only when there is a severe problem. A mixture of Sulfur and yucca has been very effective on the russet and broad mite.
  • In extreme conditions, a dose of industrial strength hydrogen peroxide can be used-very sparingly.
  • Tree wraps can help help deter rodents from chewing on the stalks and sticky tree wraps can help prevent insects from climbing up stalks.

Research the pests in your garden. If you understand a little bit of biology, research who eats who, and learn the life cycles of certain pests, you will be able to deal with them more effectively and reduce harm to the beneficials you want to keep in your garden.